We change after two beers... and after six?

After two: Uninhibited, slower reactions and yet ready for more

The notion of 'I'll just have one' continues to be a myth. Generally, when someone says they're going for a beer, it is really just a saying (then comes the 'I was going to have one but I got sucked in'). People usually get into drinking at least two, a habit that, if done occasionally, is very socially accepted because it stops at two and those two beers don't affect us... Or do they? Let's turn to the experts, whose opinions count far more than the popular version.

"A 'caña' comprises of at least 33cl of beer. If we take a standard strength beer, with 5% alcohol, that is equivalent to 17g of alcohol per beer... 34 if there are two. The numbers are going up quickly!" warned David Avellanal, a medical intern at Hospital Vithas Vitoria.

So, what can happen to the body? It depends on our weight and size (the less corpulent are more affected), age (teenagers and people over 65 need to be careful), gender (women can become inebriated faster), our drinking habits, genetics and individual metabolism... everyone reacts differently. However, looking at averages, something is clear: among non-daily drinkers a single beer in the case of women, and almost two in men, can already cause "a certain loss of inhibitions that initially helps us to socialise more and a reduction in stress, although this effect disappears quickly and we need to continue drinking to maintain it," explained Avellanal.

That's why it's hard for us to stop: that tiny intake is enough to break our self-control barrier and we say 'come on, let's go. Another, it'll be the last one'. That's it, we are totally normal, right?

We think so, but a sober onlooker would see other things in us: "With that amount, even if we don't notice it, we are already more confused, our processing speed changes and, if we have to switch from one task to another quickly, it would be noticeable... it would take a second or two longer. It seems like a small thing but, for example, on the road it can be the difference between having an accident or not," stated psychiatrist and social media blogger Rosa Molina, adding that for this reason the legal limit for driving is already set at these levels (0.5g per litre of alcohol in the blood, which is equivalent to 0.25 mg/l of exhaled air).

A man weighing 70-90kg with two beers inside him would show a blood alcohol count of 0.43 to 0.55, and a woman of the same weight from 0.68 to 0.95... In other words, both would almost certainly be over the limit (and with problems focusing).

As Molina pointed out, the body changes do not end there. "Two beers can be 'sleep-inducing', but they prevent us from reaching the restorative phases of sleep."

"There are those who can metabolise beer quickly and have more tolerance. Others (a third of Asians) get drunk on one or two beers," said Néstor Szerman, a psychiatrist at the Institute of Psychiatry and Mental Health at the Gregorio Marañón Hospital and president of the Dual Pathology Foundation. It seems that we Europeans last longer than Asians and Americans.

After six: Staggering and with self control in the 'off' position

Turning now to the question of drinking six beers: this is no longer so socially acceptable. We are crossing the line and everyone sees that. We can see it for ourselves too, (at least before the second or third, then we are past caring). The 102g of alcohol that we carry around inside us are already having effects that are very difficult to hide.

"Some fall asleep, others become uninhibited or hostile...," said Szerman, highlighting that, after a certain barrier has been passed - and six beers are usually over it - there are people who "display compulsive consumption, begin to drink more quickly and it is difficult for them to stop drinking, and all this is accompanied by changes in their levels of irritability, hostility, suspicion and loss of impulse control. This, he stresses, is especially problematic in adolescence, when "the impulsive behaviours in the brain at that age are developing".

Be that as it may, six cans of beer "already assume, in general, a high degree of intoxication," warned Molina. A man weighing 70 to 90 kilos would have a blood alcohol count greater than 1, and a woman between 2, or almost 3 if small in stature.

"Our ability to pay attention is already totally diminished as well as our psychomotor skills, so we stagger, something already very evident in most cases," said the psychiatrist. In fact, if we could see ourselves from when sober, we would perceive a great change, because we will be "more impulsive and have much less self-control, since the prefrontal cortex (the part of the brain where this ability resides) becomes 'uninhibited', so from then we can grow more aggressive and do undesirable things, like having unprotected sex, for example".

The warning from Avellanal is that at this point, with 100g of alcohol doing its thing around our body, "the initial euphoria and excitement have given way to intoxication, and such consumption is infrequent and the body is not used to it".

The word intoxicated sounds strong, but it really is just that. Alcohol is toxic and our body has problems processing and eliminating it. Especially as it is usually drunk very quickly, something that makes things worse: "The more you drink in a short space of time, (the famous 'binge-drinking'), the greater the risk of alcohol intoxication," said Avellanal. In Spain the average is 9.5 litres of alcohol consumed per person per year, mostly beer and wine... and some insist on knocking it back on the odd occasion rather than spreading out their consumption over the year. So this means putting our liver at risk, since it can only metabolise alcohol at a rate of 10 or 20ml per hour.

And if we just fall sleep, will that drunken feeling be gone faster? No, quite the opposite. The process of eliminating alcohol from the body slows down and we can wake up still blowing a positive breath test, experts warn.